How can I make a grip that is like the one on Count Dooku's lightsaber from Star Wars
The grip texture is quite easy to do.
It's just a brick texture with Bump/Displacement.




Use the Brick Texture node. Set Width and Height the same, to get that square pattern.
Connect it to the UV map and rotate it 45° using the Mapping node
Add Color ramp to control the height difference, and use it with Bump or Displacement node


You can use it with the Bump node, to fake the 3D appearance.



Or use the Displacement node, for a real 3D effect. It requires a lot of geometry. Also, don't forget to enable true displacement in the material settings.